Method and apparatus for maintaining a wireless local area network connection during a Bluetooth inquiry phase or a Bluetooth paging phase

ABSTRACT

In response to determining that a Bluetooth inquiry phase or a Bluetooth paging phase is beginning, a power save (PS) mode signal is sent from a first device to a second device via a wireless local area network (WLAN) communication link, wherein the PS mode signal indicates that the first device is in a WLAN PS mode. A PS poll signal is sent from the first device to the second device via the WLAN communication link in a gap between Bluetooth inquiry phase message transmissions during the Bluetooth inquiry phase or between Bluetooth paging phase message transmissions during the Bluetooth paging phase.

CROSS-REFERENCES TO RELATED APPLICATIONS

This is a continuation of U.S. application Ser. No. 13/346,690 entitled“METHOD AND APPARATUS FOR MAINTAINING A WIRELESS LOCAL AREA NETWORKCONNECTION DURING A BLUETOOTH INQUIRY PHASE OR A BLUETOOTH PAGING PHASE”and filed on Jan. 9, 2012, which is a continuation of U.S. applicationSer. No. 12/261,009, now U.S. Pat. No. 8,094,597, entitled “METHOD ANDAPPARATUS FOR MAINTAINING A WIRELESS LOCAL AREA NETWORK CONNECTIONDURING A BLUETOOTH INQUIRY PHASE OR A BLUETOOTH PAGING PHASE” and filedon Oct. 29, 2008, which claims the benefit of U.S. ProvisionalApplication No. 60/983,741, entitled “Coexistence by Puncturing theBluetooth Inquiry Phase” and filed on Oct. 30, 2007. The disclosures ofthe above-referenced applications are hereby incorporated by referenceherein.

FIELD OF THE TECHNOLOGY

The present disclosure relates generally to communication systems, andmore particularly, to wireless communication systems that employ firstand second wireless communication networks.

DESCRIPTION OF THE RELATED ART

Wireless communication networks continue to increase in demand asconsumers flock toward mobile computing devices and as manufacturerscontinue to develop wireless devices with greater capabilities andfeatures. Many consumers use personal wireless networks in their homes.While these networks are easy to install and provide considerablebandwidth, they do not provide communication over a very large distance.Many cities have begun arranging wireless networks on a larger scale toprovide wireless communication over a larger area.

Numerous types of wireless networks and network protocols exist.Wireless local area networks (WLAN) typically include one of the variousInstitute of Electrical and Electronics Engineers (IEEE) 802.11 standardwireless protocols, first promulgated in 1999. These protocols includeIEEE 802.11a, 802.11b, 802.11g, and 802.11n, which operate at differentspectrum bands and/or different multiplexing or spread spectrum schemesto deliver various bit rates to devices on a wireless network. Any ofthese IEEE 802.11 networks may be referred to as a “WiFi” network.

Another example of a wireless network technology is the Bluetoothwireless protocol promulgated by the Bluetooth Special Interest Group,Inc. Sometimes referred to as personal area networks or PAN, networksemploying the Bluetooth wireless protocol employ short-rangecommunications technology facilitating data transmission over shortdistances from fixed and/or mobile devices. Bluetooth networks alsoemploy frequency hopping spread spectrum, and may achieve a gross datarate of 1 megabit per second (Mb/s) (with Bluetooth version 1.2).Bluetooth networks provide a way to connect and exchange informationbetween devices such as mobile phones, telephones, laptops, personalcomputers, printers, GPS receivers, digital cameras, video gameconsoles, peripherals, etc.

Bluetooth and WiFi networks may both operate on the same frequency range(or overlapping frequency ranges), but they employ different modulationtechniques. Bluetooth may be useful when transferring informationbetween two or more devices that are near each other in low-bandwidthsituations. For example, Bluetooth is commonly used to transfer sounddata between a mobile phone and a Bluetooth-enabled wireless headset, orto transfer data between two proximately located hand-held devices(e.g., transferring files). On the other hand, WiFi providescapabilities similar to a traditional Ethernet network and provides muchhigher data rates as compared with Bluetooth. Also, because WiFi useshigher power than Bluetooth, WiFi communications can occur over greaterdistances than with Bluetooth.

Frequently, WLAN communication systems and Bluetooth communicationsystems coexist in sufficiently close proximity to one another thattransmissions of one system may interrupt, degrade, or otherwiseinterfere with transmissions of the other system. For example, when aBluetooth transmitter is located in close proximity to a WLAN receiver,transmit power emanating from the Bluetooth transmitter may desensitizeand possibly saturate the WLAN receiver such that, during the Bluetoothtransmission, a data packet being sent to the WLAN receiver by a WLANaccess point, for example, either may not be received properly by theWLAN receiver or may even not be received at all. While this problemwould not arise if WLAN data were transmitted only when the Bluetoothtransmitter was off, in practice it is likely that WLAN and Bluetoothcommunication systems will overlap in time and interfere with oneanother to some degree.

For example, a Bluetooth/WLAN compatible communication device may beoperating such that Bluetooth communications are in a Bluetooth Inquiryphase and WLAN communications are occurring with an Access Point (AP).The Bluetooth Inquiry phase can last as much as 10 seconds. During thisperiod, if the AP does not receive a WLAN transmission from thecomputing device, the AP may either disassociate with the computingdevice or the transmission rate utilized by the AP for transmitting WLANpackets to the computing device may be dropped to a very low rate. Thismay result in the WLAN throughput going down to nearly zero.

In a Bluetooth network, a Bluetooth-enabled device may seek to discoverwhat other Bluetooth-enabled devices are nearby. This may beaccomplished by a Bluetooth inquiry procedure. In the inquiry procedure,the Bluetooth-enabled device broadcasts a series of inquiry messages.Each other Bluetooth-enabled device that receives one or more of theinquiry messages may respond by transmitting back to theBluetooth-enabled device an inquiry reply message, which includes theaddress of the responding device. Based on the inquiry reply messagesthat it receives, the Bluetooth-enabled device can determine what otherBluetooth-enabled devices are nearby. Then, the Bluetooth-enabled devicemay seek to establish a connection with a selected one of the respondingdevices by transmitting a series of page messages to the selectedresponding device. In response, the selected device then transmits apage response message back to the Bluetooth-enabled device.Subsequently, additional information may be exchanged between the twodevices to permit a Bluetooth connection to be established.

SUMMARY

In one embodiment, a method includes determining that a Bluetoothinquiry phase or a Bluetooth paging phase is beginning. The method alsoincludes sending, via a wireless local area network (WLAN) communicationlink, a power save (PS) mode signal from a first device to a seconddevice in response to determining that the Bluetooth inquiry phase orthe Bluetooth paging phase is beginning. The PS mode signal indicatesthat the first device is in a WLAN PS mode. The method additionallyincludes sending, via the WLAN communication link, a PS poll signal fromthe first device to the second device in a gap between Bluetooth inquiryphase message transmissions during the Bluetooth inquiry phase orbetween Bluetooth paging phase message transmissions during theBluetooth paging phase.

The gap referred to herein between Bluetooth inquiry phase or pagingphase message transmissions may be preconfigured within the Bluetoothinquiry phase or paging phase, such as by suppressing a portion of theBluetooth paging or inquiry transmission, or, alternatively, the gap maybe created to accommodate a received WLAN PS mode signal, such as byproviding a portion of the Bluetooth paging or inquiry transmission witha relatively low priority and providing a WLAN PS mode signal with arelatively high priority such that the WLAN PS mode signal willeffectively take the place of that portion of the Bluetooth inquiry orpaging transmission according to an arbitration process.

In another embodiment, an apparatus comprises a power save (PS) modesignal generator configured to cause a PS mode signal to be sent from afirst device to a second device via a wireless local area network (WLAN)communication link in response to determining that a Bluetooth inquiryphase or a Bluetooth paging phase is beginning. The PS mode signalindicates that the first device is in a WLAN PS mode. Additionally, theapparatus comprises a timing device to generate an enable signal duringa gap between Bluetooth inquiry phase message transmissions during theBluetooth inquiry phase or between Bluetooth paging phase messagetransmissions during the Bluetooth paging phase. The apparatus alsocomprises a PS poll signal generator coupled to the timing device. ThePS poll signal generator is configured to cause a PS poll signal to besent from the first device to the second device via the WLANcommunication link in the gap between Bluetooth inquiry phase messagetransmissions during the Bluetooth inquiry phase or between Bluetoothpaging phase message transmissions during the Bluetooth paging phasebased on the enable signal.

In yet another embodiment, an apparatus comprises a means for causing apower save (PS) mode signal to be sent from a first device to a seconddevice via a wireless local area network (WLAN) communication link inresponse to determining that a Bluetooth inquiry phase or a Bluetoothpaging phase is beginning. The PS mode signal indicates that the firstdevice is in a WLAN PS mode. The apparatus additionally comprises ameans for causing a PS poll signal to be sent from the first device tothe second device via the WLAN communication link in a gap betweenBluetooth inquiry phase message transmissions during the Bluetoothinquiry phase or between Bluetooth paging phase message transmissionsduring the Bluetooth paging phase.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an example communication system in whichWLAN and Bluetooth communications coexist;

FIG. 2 is a block diagram of a system including a mobile communicationdevice communicating with a Bluetooth compatible device and an AccessPoint (AP);

FIG. 3 is a diagram of a communication system including a mobilecommunication device communicating with a headset device via a Bluetoothconnection and communicating with an access point (AP) over a WLANconnection;

FIG. 4 is a timing diagram illustrating an example process in which WLANcommunications occur during a Bluetooth inquiry phase;

FIG. 5 is a block diagram of an example Bluetooth inquiry phase modulefor a WLAN control block corresponding to a WLAN interface;

FIG. 6 is a flow diagram of an example method for implementing WLANcommunications occur during a Bluetooth inquiry phase; and

FIGS. 7A-7E are various examples of devices that may utilize techniquessuch as described herein for implementing WLAN communications during aBluetooth inquiry phase or during a Bluetooth paging phase.

DETAILED DESCRIPTIONS

FIG. 1 is a block diagram of an example wireless communication system100 in which WLAN transmissions and Bluetooth transmissions may coexist.The system 100 includes a WLAN access point 102 which may be coupledwith a plurality of wireless stations 104, 105 for WLAN communicationsbetween the access point and each of the wireless stations 104, 105.Each of the wireless stations 104, 105 and the access point 102 maycommunicate according to one or more of the Institute of Electrical andElectronics Engineering (IEEE) 802.11 Standards, for example, or anyother desired WLAN protocol, as indicated by the WLAN communicationsignals 106, 107.

As shown in FIG. 1, the wireless station 105 is Bluetooth-enabled. Inother words, in addition to receiving WLAN data packets from the accesspoint 102 of the wireless local area network 100, the wireless station105 also is capable of connecting to and communicating with a headset orany other suitable Bluetooth-enabled device 108 via a Bluetoothconnection 110. In order to establish the Bluetooth connection 110, thewireless station 105 may utilize the Bluetooth inquiry and pagingprocedures discussed above. During these procedures, the wirelessstation 105 may transmit a series of messages (e.g., inquiry and pagingmessages). These messages are typically transmitted in succession, withrelatively small time periods in between messages. Thus, if the device105 were to receive a WLAN packet from the AP 102 during a Bluetoothinquiry phase or during a Bluetooth paging phase, the WLAN packet likelywould not be received correctly because of interference caused by thetransmission of Bluetooth inquiry or paging messages. On the other hand,in example implementations to be described in more detail below, aBluetooth interface of the wireless station 105 may be configured toinclude one or more gaps between Bluetooth inquiry messages and/orbetween Bluetooth paging messages. In these implementations, a WLANinterface is configured to inform the AP 102 that device 105 isoperating in a power save (PS) mode (sometimes referred to as a powermanagement (PM) mode) during the Bluetooth inquiry phase and/or duringthe Bluetooth paging phase. Then, the WLAN interface may send PS pollsignals to the AP 102 during gaps between Bluetooth inquiry messagesand/or gaps between Bluetooth paging messages, which causes the AP 102to send packets during the gaps between Bluetooth inquiry messagesand/or the gaps between Bluetooth paging messages in response to the PSpoll signals. Thus, interference between a received WLAN packet andBluetooth inquiry messages and/or Bluetooth paging messages may beavoided. As described above, rather than configuring the wirelessstation 105 to include gaps by suppressing Bluetooth transmissions,coexistence may be enabled by according a lower priority to certain ofthe Bluetooth transmissions than the priority accorded to the WLAN PSpoll signals so that the latter signals can be transmitted when theBluetooth transmissions would otherwise be transmitted. An arbitratorcan determine whether a Bluetooth inquiry or paging message should betransmitted, or if a WLAN PS poll signal should be transmitted based onpriorities associated with the Bluetooth inquiry or paging message andthe WLAN PS poll signal.

The relative placement of gaps in the Bluetooth inquiry or pagingmessage (i.e., the puncturing pattern) may be designed judiciously in aneffort to minimize the reduction in the probability of a successfulsynchronization for the inquiry or paging process. A so-called “odd”interval of puncturing will distribute the suppressed packets (orpotentially suppressed packets if suppression based on priorities isutilized) relatively evenly among the selected RF channels, because theinquiry/paging process has a repetition of 16 channels, and an oddnumber interval will ensure suppression on a different channel throughevery repetition until a packet in each of the 16 channels has beendropped once. At that point, the puncturing pattern will have loopedback to the beginning. A longer interval between gaps will lower thedegradation of Bluetooth service caused by the gaps. A shorter intervalwill make more bandwidth available to the WLAN system. The puncturingpattern may drop or suppress consecutive packets, provided that thenumber of consecutive packets dropped/suppressed is less than theinterval and the interval is odd.

FIG. 2 is a block diagram illustrating an exemplary system 200 includinga mobile communication device 250 interacting with aBluetooth-compatible headset 259 and an access point 270. Referring toFIG. 2 in conjunction with FIG. 1, the first mobile communication device250 may include a cellular antenna 251 and either or both signalprocessing and/or control circuits 252. The mobile communication device250 may also include a WLAN network interface 268, and a Bluetoothinterface 269. The WLAN network interface 268 may include, or be coupledto, a WLAN control block (not shown). The Bluetooth interface 269 mayinclude, or be coupled to, a Bluetooth control block (not shown). TheWLAN control block and the Bluetooth control block may be coupledtogether. Optionally, the WLAN control block and/or the Bluetoothcontrol block may be included in the signal processing and/or controlblock 252. In some implementations, the mobile communication device 250includes a microphone 256, an audio output 258 such as a speaker and/oraudio output jack, a display 260 and/or an input device 262 such as akeypad, pointing device, voice actuation and/or other input device.Secondary devices 259 and 270, for example, a hands-free headset unitand AP respectively, may communicate with the device 250. The signalprocessing and/or control circuits 252 may also process data, performcoding and/or encryption, perform calculations, format data and/orperform other mobile phone functions.

The mobile communication device 250 may include a mass data storage 264that stores data in a nonvolatile manner such as optical and/or magneticstorage devices, for example, hard disk drives HDD and/or DVDs. Themobile communication device 250 may include a memory 266 such as RAM,ROM, low latency nonvolatile memory such as flash memory and/or othersuitable electronic data storage. The mobile communication device 250also may support connections with a wireless network via the WLANinterface 268. The Bluetooth control block may be configured to causethe Bluetooth interface 269 to include one or more gaps betweenBluetooth inquiry messages and/or to include one or more gaps betweenBluetooth paging messages that are transmitted by the device 250. TheWLAN control block may be configured to cause the device 250 to transmita signal to the AP 270 to inform the AP 270 that the device 250 is inthe PS mode during the Bluetooth inquiry phase and/or during theBluetooth paging phase. Then, the WLAN control block may cause thedevice 250 to send PS poll signals to the AP 270 during gaps betweenBluetooth inquiry messages and/or gaps between Bluetooth pagingmessages, which in turn causes the AP 270 to send packets in response tothe PS poll signals during the gaps between Bluetooth inquiry messagesand/or the gaps between Bluetooth paging messages. Thus, interferencebetween a received WLAN packet and Bluetooth inquiry messages and/orBluetooth paging messages may be avoided. In some embodiments, aWLAN/Bluetooth arbitrator 267 may be coupled to the WLAN interface 268and the Bluetooth interface 269 as shown in FIG. 2 to arbitrate whichinterface is permitted to communicate at any given time based on apriority value assigned to the communication of each interface. Forexample, the WLAN/Bluetooth arbitrator 267 may grant one of the WLANinterface 268 or the Bluetooth interface 269 the ability to transmit ina particular interval based on priorities of the transmissions.Additionally or alternatively, if a single antenna (not shown) isemployed instead of the two antennae illustrated in FIG. 2, theWLAN/Bluetooth arbitrator 267 also may be configured to operate a switchthat controls, based on priorities, whether the WLAN interface 268 orthe Bluetooth interface 269 is coupled to the single antenna.

FIG. 3 is a block diagram of another example wireless network 300, whichmay represent a short-range or long-range network and which may includean ad hoc topology and/or infrastructure topology with a firstcommunication device 302 (shown as a handheld communication device)wirelessly communicating with secondary communication devices 304 (shownas an AP) and 306 (depicted as a Bluetooth-ready headset worn by auser). In the illustrated example, the first communication device 302may be a Portable digital assistant (PDA), a cellular phone, a componentof a vehicle, a media player, a laptop computer, a wireless supporteddesktop computer, a gaming system, a wireless networking device such asa router, a switch, etc., or any other computing device. Similarly, thesecondary communication devices 304 and 306 may be any of a variety ofcomputing devices, such as described above with respect to the firstcommunication device 302. In a WLAN environment, the first communicationdevice 302 and the secondary communication devices 304 and 306 may becompliant with one of the accepted or contemplated WLAN communicationprotocols, of which IEEE 802.11a, 802.11b, 802.11g, 802.11n, areexamples. The communication devices 302 and 306 also may be compliantwith the Bluetooth (BT) communication protocol. But these communicationprotocols are provided only by way of example. The mobile communicationdevices 302, 304, 306 may operate under other wireless communicationprotocols as desired.

The first communication device 302 may wirelessly communicate with thetwo secondary communication devices 304 and 306. For instance,communication between the device 302 and the device 304 may be achievedusing the WLAN connection 310. Additionally, the device 302 may seek toestablish a Bluetooth connection 308 with the device 306. A Bluetoothinterface of the first device 302 may be configured to include one ormore gaps between Bluetooth inquiry messages and/or to include one ormore gaps between Bluetooth paging messages. In these implementations, aWLAN interface of the first device 302 is configured to inform thesecondary device 304 that the device 302 is operating in the PS modeduring the Bluetooth inquiry phase and/or during the Bluetooth pagingphase. Then, the WLAN interface may send PS poll signals to the device304 during gaps between Bluetooth inquiry messages and/or gaps betweenBluetooth paging messages, which causes the device 304 to send packetsduring the gaps between Bluetooth inquiry messages and/or the gapsbetween Bluetooth paging messages in response to the PS poll signals.Thus, interference between a received WLAN packet and Bluetooth inquirymessages and/or Bluetooth paging messages may be avoided.

FIG. 4 is timing diagram 400 illustrating an example process by whichWLAN communications and Bluetooth communications may coexist. FIG. 4will be described with reference to FIG. 2 for ease of explanation. Itis to be understood, however, that the described techniques may beapplied to other situations in which a device is communicating on both aWLAN connection and a Bluetooth connection. In the example process ofFIG. 4, a time-sharing scheme is generally utilized. For example,Bluetooth inquiry messages and/or Bluetooth paging messages may bespaced apart so that WLAN transmissions may occur in between theBluetooth transmissions.

FIG. 4 will be described in the context of a discovery process such asthe Bluetooth inquiry phase, but those skilled in the art will readilyappreciate that the described process also may be applied during asynchronization process such as the Bluetooth paging phase. TheBluetooth inquiry phase may have a duration of any suitable time suchas, for example, 10 seconds. During the Bluetooth inquiry phase, thedevice 250 may transmit a plurality of inquiry messages 406. Theduration of each Bluetooth inquiry message 406 may be 68 μs(microseconds), for example. Additionally, the Bluetooth control block(or the Bluetooth WLAN arbitrator 267 where provided) may be configuredto cause gaps to be included between at least some of the Bluetoothinquiry messages 406. For example, in FIG. 4, there is a gap between twoBluetooth inquiry message transmissions 406 of 2.5 ms. Other gap lengthsmay also be utilized. For instance, the Bluetooth standard permits gapsof up to four Bluetooth inquiry message lengths (i.e., 625 μs perBluetooth inquiry message×4=2.5 ms) between Bluetooth inquiry messages.Additionally, in FIG. 4, the inquiry message transmissions 406 includetwo consecutive Bluetooth inquiry messages, thus each inquiry messagetransmission 406 has a length of 1.25 ms (i.e., 625 μs per Bluetoothinquiry message×2=1.25 ms). Of course, inquiry message transmissions 406may have different lengths such as a length of one Bluetooth inquirymessage or a length of three, four, five, etc., Bluetooth inquirymessages.

When the Bluetooth interface 269 is to begin operating in an inquiryphase, the Bluetooth control block may send a signal (at a timeindicated by dashed line 401) such as an interrupt signal to the WLANcontrol block to inform the WLAN control block that a Bluetooth inquiryphase will soon begin. The Bluetooth control block may be configured tosend the signal at a time T1 prior to when the inquiry phase is tobegin. The time T1 may be preconfigured and known ahead of time by boththe Bluetooth control block and the WLAN control block. Alternatively,the Bluetooth control block may inform the WLAN control block of thetime T1 via the signal indicating the Bluetooth inquiry phase will soonbegin or another signal, for example. After receiving the signal fromthe Bluetooth control block indicating that the Bluetooth inquiry phasewill soon begin, the WLAN control block may cause the WLAN interface 268to send a signal 402 to the access point 270 indicating that the device250 is in a power save mode. The signal 402 may be a packet, such as anull packet, indicating the communication device 250 is going into thePS mode. For example, the packet 402 may include a PS bit set to a valueto indicate that the communication device 250 is going into the PS mode.The AP 270 may send an acknowledgment packet 404 in response to thesignal 402. The AP 270 may interpret the PS signal in the null packet402 to mean that the AP 270 can transmit packets (besides acknowledgmentpackets) to the communication device 250 via the WLAN link only inresponse PS poll signals sent by the device 250.

Also upon receiving the signal from the Bluetooth control blockindicating that the Bluetooth inquiry phase will soon begin, the WLANcontrol block may start a timer device included in the WLAN controlblock. The timer device may be configured to generate a control signalthat indicates when the PS poll message can be sent to the AP 270 duringthe Bluetooth inquiry phase. For instance, if the control signal isactive, this may indicate that the PS poll message can be sent to the AP270, whereas an inactive control signal may indicate that the PS pollmessage should not be sent. The timer device may be configured togenerate a control signal that is active after the time 401 and untilsome time prior to the beginning of the first Bluetooth inquiry phasetransmission 406. For example, if it is known that the first Bluetoothinquiry phase transmission 406 is to occur T1 ms after the time 401, thetimer device may be configured to cause the control signal to be activefrom time 401 until a time T1 ms−DELTA, where DELTA is a time periodbased on an estimate of time required for the communication device 250to transmit a packet, such as the PS poll message, to the AP 270, toreceive an acknowledgment from the AP 270 in response to the PS poll,and to receive a packet, if one is available, from the access point 270in response to the PS poll. Optionally, the time DELTA may also takeinto account the time to send an acknowledgment from the device 250 tothe AP 270. Optionally, the WLAN control block may be configured tocause PS poll messages to be sent prior to the first Bluetooth inquiryphase transmission 406 and if the timer device control signal is active.Alternatively, the WLAN control block may be configured to cause onlythe signal 402 to be sent prior to the first Bluetooth inquiry phasetransmission 406. In this implementation, the timer device optionallymay be configured to cause the control signal to be inactive from thetime 401 to the end of the first Bluetooth inquiry phase transmission406.

The timer device may be configured to cause the control signal to goactive after the end of each Bluetooth inquiry phase transmission 406(except, optionally, for the last Bluetooth inquiry phase transmission406 in an inquiry phase) and then go inactive at some desired orpre-determined time before the beginning of the next Bluetooth inquiryphase message transmission 406. In the example of FIG. 4, it is known orexpected, for instance, that there is a gap of 2.5 ms between theBluetooth inquiry phase transmissions 406. Thus, the timer device may beconfigured to cause the control signal to go active when a Bluetoothinquiry phase transmission 406 ends until a time 2.5 ms−DELTA after theBluetooth inquiry phase transmission 406.

If the WLAN control block has knowledge of the time period T1, thelength of each Bluetooth inquiry phase transmission 406, and the lengthof the gap between each of the Bluetooth inquiry phase transmissions406, the timer device may be able to generate the control signal bybeing informed of the time 401, such as by the signal from the Bluetoothcontrol block indicating that the Bluetooth inquiry phase will soonbegin. The time period T1, the length of each Bluetooth inquiry phasetransmission 406, and the length of the gap between each of theBluetooth inquiry phase transmissions 406 may be preconfigured and/or orpre-known by the WLAN control block. Optionally, the Bluetooth controlblock may send this information to the WLAN control block. In oneimplementation, the Bluetooth control block may send a signal, such asan interrupt signal, indicating the end of each Bluetooth inquirytransmission 406. The timer device may then utilize the signalindicating the end of each Bluetooth inquiry transmission 406 togenerate the timer device control signal.

Between Bluetooth inquiry transmissions 406, the WLAN control block maybe configured to cause one or more PS poll signals 408 to be sent to theAP 270 if the control signal from the timer device is active. Inresponse, the AP 270 may transmit an acknowledgment 410, and a packet412, if a corresponding one is available, to the device 250 in responseto each PS poll signal 408.

Optionally, at the end of the Bluetooth inquiry phase, the WLAN controlblock may cause the WLAN interface 268 to send a signal (not shown inFIG. 4) to the access point 270 indicating that the device 250 is nolonger in the PS mode. The signal indicating that the device 250 is nolonger in the PS mode may be a packet, such as a null packet, indicatingthe communication device 250 is going not in the PS mode. For example,the null packet may include a PS bit set to a value to indicate that thecommunication device 250 is not in the PS mode. The AP 270 may send anacknowledgment packet (not shown in FIG. 4) in response to the signalindicating that the device 250 is no longer in the PS mode. The WLANcontrol block may determine the end of the Bluetooth inquiry phase in avariety of ways. For example, if the length of the Bluetooth inquiryphase is already known to the WLAN control block, the timer device maygenerate a signal indicating the end of the inquiry phase.Alternatively, the Bluetooth control block may send a signal such as aninterrupt signal to the WLAN control block to inform the WLAN controlblock that the Bluetooth inquiry phase has ended.

FIG. 5 is a block diagram of an example Bluetooth inquiry phase module450 for a WLAN control block. For instance, the module 450 may beincluded in a WLAN control block. The module 450 may be utilized forgenerating WLAN control signals during a Bluetooth inquiry phase such asin the process discussed above with reference to FIG. 4. Of course, theprocess discussed above with respect to FIG. 4 may be implemented usinga module other than the module 450.

The module 450 may include a PS mode signal generator 454, a timingdevice 458 and a PS poll message generator 462. The PS mode signalgenerator 454 generates WLAN signals to be sent to an AP indicating tothe AP that the communication device (in which the module 450 isincluded) is in or out of the PS mode. For example, when thecommunication device is to begin a Bluetooth inquiry phase, the PS modesignal generator 454 may generate a signal (such as a null packet with aPS parameter or bit set) to be sent to the AP indicating that thecommunication device is in the PS mode. The PS mode signal generator 454may generate the signal indicating that the communication device is inthe PS mode in response to a signal, such as an interrupt signal, fromthe Bluetooth control block indicating that a Bluetooth inquiry phase isabout to begin. Alternatively, the PS mode signal generator 454 maygenerate the signal indicating that the communication device is in thePS mode in response to a signal from timing device 458 indicating that aBluetooth inquiry phase is about to begin.

When the communication device is to leave the Bluetooth inquiry phase,the PS mode signal generator 454 may generate a signal (such as a nullpacket with a PS parameter or bit cleared) to be sent to the APindicating that the communication device is out of the PS mode. The PSmode signal generator 454 may generate the signal indicating that thecommunication device is not in the PS mode in response to a signal fromthe timing device 458 indicating that the Bluetooth inquiry phase hasended. Alternatively, the PS mode signal generator 454 may generate thesignal indicating that the communication device is in the PS mode inresponse to a signal, such as an interrupt signal, from the Bluetoothcontrol block indicating that the Bluetooth inquiry phase has ended.

The timing device 458 may operate as discussed above with respect toFIG. 4. For example, the timing device 458 may generate a control orenable signal that causes or enables the PS poll message generator 462to generate PS poll messages in gaps between Bluetooth inquiry messagetransmissions during the Bluetooth inquiry phase. The timing device 458may receive the signal from the Bluetooth control block indicating thata Bluetooth inquiry phase is about to begin. The timing device 458optionally may receive or have access to additional information such asone or more of an indication of the time period T1, an indication of thelength of Bluetooth inquiry phase message transmissions, an indicationof the length of the gaps between Bluetooth inquiry phase messagetransmissions, signals indicating when each Bluetooth inquiry phasemessage transmission begins, a signal indicating when the Bluetoothinquiry phase has ended, etc. The timing device 458 may include one ormore timers and control components for controlling the one or moretimers. The timer device 458 may include a state machine, for example.

The PS poll message generator 462 may generate PS poll messages in gapsbetween Bluetooth inquiry message transmissions during the Bluetoothinquiry phase based on the enable signal from the timing device 458.

A module similar to the module 450 could be utilized for controllingWLAN communications during the Bluetooth paging phase. Such a modulealso may be included in a WLAN control block. Alternatively, the module450 could be configured to generate WLAN control signals during both theBluetooth inquiry phase and the Bluetooth paging phase.

FIG. 6 is a flow diagram of an example method 500 for controlling WLANcommunications during the Bluetooth inquiry phase. The method 500assumes that the Bluetooth control block has been configured to includeone or more gaps between Bluetooth inquiry message transmissions duringthe Bluetooth inquiry phase. The method 500 may be implemented utilizinga WLAN control block that includes a module such as the example module450 of FIG. 5. For ease of explanation, the method 500 will be describedwith reference to FIG. 5. It will be understood, however, that themethod 500 may be implemented by a WLAN control block that includes amodule other than the module 450.

At a block 502, it is determined whether the Bluetooth inquiry phase isstarting. For example, the WLAN control block may receive a signal fromthe Bluetooth control block indicating that the Bluetooth inquiry phasewill soon begin. The signal optionally may indicate when the Bluetoothinquiry phase will begin. As another option, the Bluetooth control blockmay be configured to send the signal at a time period T1 prior to theBluetooth inquiry phase beginning, where the time period T1 is known bythe WLAN control block. The WLAN control block may determine that theBluetooth inquiry phase is beginning based on the signal received fromthe Bluetooth control block. In the example of FIG. 5, the timer device458 and, optionally, the PS mode signal generator 454 may determinewhether the Bluetooth inquiry phase is starting based on the indicatorsignal from the Bluetooth control block.

At a block 504, the AP may be informed that the device is entering thePS mode. For example, the PS mode signal generator 454 may cause anindication such as, for example, a null packet with a PS mode parameteror bit set, to be sent to the AP in response to the signal from theBluetooth control block, or a signal from the timer device 458indicating that the Bluetooth inquiry phase is about to begin.

At an optional block 506, one or more PS poll messages may be sent tothe AP prior to a first Bluetooth inquiry message transmission. Forinstance, if the time period T1 permits, the device may attempt to getone or more packets from the AP prior to the first Bluetooth inquirymessage transmission by prompting the AP with one or more PS pollmessages. The timer device 458 may be configured to cause the control orenable signal to be active for a time prior to the first Bluetoothinquiry message transmission. Thus, the PS poll message generator 462may cause one or more PS poll messages to be sent to the AP prior to thefirst Bluetooth inquiry message transmission. The block 506 may beomitted.

At a block 508, it may be determined if a gap between Bluetooth inquiryphase transmissions has started. For example, the timer device 458 maydetermine if a gap between Bluetooth inquiry phase transmissions hasstarted. If it is determined that the gap has started, the timer device458 may cause the enable signal to be active.

At a block 510, a PS poll message may be sent to the AP. For example,the PS poll message generator 462 may cause a PS poll message to be sentto the AP.

Ata block 512, it may be determined if the gap is about to end. Forexample, it may be determined if a time period DELTA prior to the end ofthe gap has been reached. The timer device 458 may determine if the gapis about to end. If it is determined that the gap is not about to end,the flow may proceed back to the block 510, at which another PS pollmessage may be generated. If, however, it is determined that the gap isabout to end, the timer device 458 may cause the enable signal to beinactive, and the flow may proceed to a block 514.

At the block 514, it may be determined if the inquiry phase has ended.For example, it may be determined whether the last Bluetooth inquirymessage transmission has ended. The timer device 458 may determine ifthe Bluetooth inquiry phase has ended. If it determined that theBluetooth inquiry phase has not ended, the flow may proceed to the block508. On the other hand, if it determined that the Bluetooth inquiryphase has ended, the flow may proceed to a block 516.

At the block 516, the AP may be informed that the device is no longer inPS mode. For example, the timing device 454 may generate a signalindicating that the Bluetooth inquiry phase has ended, and this signalmay be provided to the PS mode signal generator 454. Alternatively, theBluetooth control block may generate the signal indicating that theBluetooth inquiry phase has ended. In response to the signal indicatingthat the Bluetooth inquiry phase has ended, the PS mode signal generator454 may cause a signal, such as a null packet with a PS mode bit orparameter cleared, to be sent to the AP to inform the AP that the deviceis no longer in the PS mode.

A method similar to the method 500 could be utilized for controllingWLAN communications during the Bluetooth paging phase. Such a method maybe implemented utilizing a WLAN control block.

Techniques such as described above for maintaining WLAN communicationsduring a Bluetooth inquiry phase and/or during a Bluetooth paging phasemay be utilized in a variety of devices that have both WLAN andBluetooth capabilities. Referring now to FIGS. 7A-7E, various exampledevices are shown that may utilize such techniques. Referring to FIG.7A, such techniques may be utilized in a high definition television(HDTV) 620. The HDTV 620 includes signal processing and/or controlcircuits, which are generally identified in FIG. 7A at 622, and a massdata storage 627. HDTV 620 receives HDTV input signals in either a wiredor wireless format and generates HDTV output signals for a display 626.In some implementations, signal processing circuit and/or controlcircuit 622 and/or other circuits (not shown) of HDTV 620 may processdata, perform coding and/or encryption, perform calculations, formatdata and/or perform any other type of HDTV processing that may berequired.

HDTV 620 may communicate with mass data storage 627 that stores data ina nonvolatile manner such as optical and/or magnetic storage devices.The mass data storage 627 may include one or more hard disk drives(HDDs) and/or one or more digital versatile disks (DVDs). One or more ofthe HDDs may be a mini HDD that includes one or more platters having adiameter that is smaller than approximately 1.8″. HDTV 620 may beconnected to memory 628 such as RAM, ROM, low-latency nonvolatile memorysuch as flash memory and/or other suitable electronic data storage. HDTV620 also may support wireless connections with a WLAN via a WLAN networkinterface 629. HDTV 620 also may support wireless connections withBluetooth enabled devices via a Bluetooth interface 625. The WLANnetwork interface 629 may include, or be coupled to, a WLAN controlblock (not shown). The Bluetooth interface 625 may include, or becoupled to, a Bluetooth control block (not shown). The WLAN controlblock and the Bluetooth control block may be coupled together.Optionally, the WLAN control block and/or the Bluetooth control blockmay be included in the signal processing and/or control block 622. TheHDTV 620 may utilize techniques such as described above to eithermaintain a connection between a HDTV 620 and an access point or enablethe access point to send WLAN packets to the HDTV 620 during a Bluetoothinquiry phase and/or a Bluetooth paging phase, for example.

Referring now to FIG. 7B, techniques such as described above may beutilized in a control system of a vehicle 630. In some implementations,a powertrain control system 632 receives inputs from one or more sensorssuch as temperature sensors, pressure sensors, rotational sensors,airflow sensors and/or any other suitable sensors and/or that generatesone or more output control signals such as engine operating parameters,transmission operating parameters, and/or other control signals.

A control system 640 may likewise receive signals from input sensors 642and/or output control signals to one or more output devices 644. In someimplementations, control system 640 may be part of an anti-lock brakingsystem (ABS), a navigation system, a telematics system, a vehicletelematics system, a lane departure system, an adaptive cruise controlsystem, a vehicle entertainment system such as a stereo, DVD, compactdisc and the like. Still other implementations are contemplated.

Powertrain control system 632 may communicate with mass data storage 646that stores data in a nonvolatile manner. Mass data storage 646 mayinclude optical and/or magnetic storage devices for example hard diskdrives HDD and/or DVDs. One or more of the HDDs may be a mini HDD thatincludes one or more platters having a diameter that is smaller thanapproximately 1.8″. Powertrain control system 632 may be connected tomemory 647 such as RAM, ROM, low-latency nonvolatile memory such asflash memory and/or other suitable electronic data storage. Powertraincontrol system 632 and/or control system 640 also may support wirelessconnections with a WLAN via a WLAN network interface 648. Powertraincontrol system 632 and/or control system 640 also may support wirelessconnections to Bluetooth enabled devices via a Bluetooth interface 645.The WLAN network interface 648 may include, or be coupled to, a WLANcontrol block (not shown). The Bluetooth interface 645 may include, orbe coupled to, a Bluetooth control block (not shown). The WLAN controlblock and the Bluetooth control block may be coupled together.Optionally, the WLAN control block and/or the Bluetooth control blockmay be included in Powertrain control system 632 and/or control system640. The vehicle 630 may utilize techniques such as described above toeither maintain a connection between a vehicle and an access point orenable the access point to send WLAN packets to the vehicle during aBluetooth inquiry phase and/or during a Bluetooth paging phase, forexample.

Referring now to FIG. 7C, techniques such as described above may beutilized in a set top box 680. The set top box 680 includes signalprocessing and/or control circuits, which are generally identified inFIG. 7C at 684, and a mass data storage device 690. Set top box 680receives signals from a source such as a broadband source and outputsstandard and/or high-definition audio/video signals suitable for adisplay 688 such as a television and/or monitor and/or other videoand/or audio output devices. Signal processing and/or control circuits684 and/or other circuits (not shown) of the set top box 680 may processdata, perform coding and/or encryption, perform calculations, formatdata and/or perform any other set top box function.

Set top box 680 may communicate with mass data storage 690 that storesdata in a nonvolatile manner. Mass data storage 690 may include opticaland/or magnetic storage devices for example hard disk drives HDD and/orDVDs. At least one HDD may be a mini HDD that includes one or moreplatters having a diameter that is smaller than approximately 1.8″. Settop box 680 may be connected to memory 694 such as RAM, ROM, low-latencynonvolatile memory such as flash memory and/or other suitable electronicdata storage. Set top box 680 also may support wireless connections witha WLAN via the WLAN network interface 696. Set top box 680 also maysupport wireless connections to Bluetooth enabled devices via aBluetooth interface 695. The WLAN network interface 696 may include, orbe coupled to, a WLAN control block (not shown). The Bluetooth interface695 may include, or be coupled to, a Bluetooth control block (notshown). The WLAN control block and the Bluetooth control block may becoupled together. Optionally, the WLAN control block and/or theBluetooth control block may be included in signal processing/controlblock 684. Set top box 680 may utilize techniques such as describedabove to either maintain a connection between the Set top box 680 and anaccess point or enable the access point to send WLAN packets to the Settop box 680 during a Bluetooth inquiry phase and/or during a Bluetoothpaging phase.

Referring now to FIG. 7D, techniques such as described above may beutilized in a media player 700. The media player 700 may include signalprocessing and/or control circuits, which are generally identified inFIG. 7D at 704, and a mass data storage device 710. In someimplementations, media player 700 includes a display 707 and/or a userinput 708 such as a keypad, touchpad and the like. In someimplementations, media player 700 may employ a graphical user interface(GUI) that typically employs menus, drop down menus, icons and/or apoint-and-click interface via display 707 and/or user input 708. Mediaplayer 700 further includes an audio output 709 such as a speaker and/oraudio output jack. Signal processing and/or control circuits 704 and/orother circuits (not shown) of media player 700 may process data, performcoding and/or encryption, perform calculations, format data and/orperform any other media player function.

Media player 700 may communicate with mass data storage 710 that storesdata such as compressed audio and/or video content in a nonvolatilemanner. In some implementations, the compressed audio files includefiles that are compliant with MP3 format or other suitable compressedaudio and/or video formats. The mass data storage may include opticaland/or magnetic storage devices for example hard disk drives HDD and/orDVDs. At least one HDD may be a mini HDD that includes one or moreplatters having a diameter that is smaller than approximately 1.8″.Media player 700 may be connected to memory 714 such as RAM, ROM,low-latency nonvolatile memory such as flash memory and/or othersuitable electronic data storage. Media player 700 also may supportwireless connections with a WLAN via a WLAN network interface 716. Mediaplayer 700 also may support wireless connections to Bluetooth enableddevices via a Bluetooth interface 715. The WLAN network interface 716may include, or be coupled to, a WLAN control block (not shown). TheBluetooth interface 715 may include, or be coupled to, a Bluetoothcontrol block (not shown). The WLAN control block and the Bluetoothcontrol block may be coupled together. Optionally, the WLAN controlblock and/or the Bluetooth control block may be included in signalprocessing/control block 704. Media player 700 may utilize techniquessuch as described above to either maintain a connection between a mediaplayer 700 and an access point or enable the access point to send WLANpackets to the media player 700 during a Bluetooth inquiry phase and/ora Bluetooth paging phase, for example.

Referring to FIG. 7E, techniques such as described above may be utilizedin a Voice over Internet Protocol (VoIP) phone 750 that may include anantenna 752, signal processing and/or control circuits 754, and a massdata storage 756. In some implementations, VoIP phone 750 includes, inpart, a microphone 758, an audio output 760 such as a speaker and/oraudio output jack, a display monitor 762, an input device 764 such as akeypad, pointing device, voice actuation and/or other input devices, anda WLAN interface 766. Signal processing and/or control circuits 754and/or other circuits (not shown) in VoIP phone 750 may process data,perform coding and/or encryption, perform calculations, format dataand/or perform other VoIP phone functions.

VoIP phone 750 may communicate with mass data storage 756 that storesdata in a nonvolatile manner such as optical and/or magnetic storagedevices, for example hard disk drives HDD and/or DVDs. The HDD may be amini HDD that includes one or more platters having a diameter that issmaller than approximately 1.8″. VoIP phone 750 may be connected tomemory 757, which may be a RAM, ROM, low-latency nonvolatile memory suchas flash memory and/or other suitable electronic data storage. VoIPphone 750 is configured to establish communications link with a VoIPnetwork (not shown) via WLAN interface 766. VoIP phone 750 also maysupport wireless connections to Bluetooth enabled devices via aBluetooth interface 765. The WLAN interface 766 may include, or becoupled to, a WLAN control block (not shown). The Bluetooth interface765 may include, or be coupled to, a Bluetooth control block (notshown). The WLAN control block and the Bluetooth control block may becoupled together. Optionally, the WLAN control block and/or theBluetooth control block may be included in signal processing/controlblock 754. VoIP phone 750 may utilize techniques such as described aboveto either maintain a connection between a VoIP phone 750 and an accesspoint or enable the access point to send WLAN packets to the VoIP phone750 during a Bluetooth inquiry phase and/or during a Bluetooth pagingphase, for example.

In each of the embodiments of FIGS. 7A-7E, a WLAN/Bluetooth arbitratormay be coupled to the WLAN interface and the Bluetooth interface, asdescribed above in relation to FIG. 2, to arbitrate which one of theinterfaces is permitted to communicate at any given time based on apriority value assigned to the communication of each interface. Also, asingle antenna may be employed instead of two antennae, and theWLAN/Bluetooth arbitrator may be configured to operate a switch thatcontrols whether the WLAN interface or the Bluetooth interface iscoupled to the single antenna.

The various blocks, operations, and techniques described above may beimplemented in hardware, firmware, software, or any combination ofhardware, firmware, and/or software. When implemented in software, thesoftware may be stored in any computer readable memory such as on amagnetic disk, an optical disk, or other storage medium, in a RAM or ROMor flash memory of a computer, processor, hard disk drive, optical diskdrive, tape drive, etc. Likewise, the software may be delivered to auser or a system via any known or desired delivery method including, forexample, on a computer readable disk or other transportable computerstorage mechanism or via communication media. Communication mediatypically embodies computer readable instructions, data structures,program modules or other data in a modulated data signal such as acarrier wave or other transport mechanism. The term “modulated datasignal” means a signal that has one or more of its characteristics setor changed in such a manner as to encode information in the signal. Byway of example, and not limitation, communication media includes wiredmedia such as a wired network or direct-wired connection, and wirelessmedia such as acoustic, radio frequency, infrared and other wirelessmedia. Thus, the software may be delivered to a user or a system via acommunication channel such as a telephone line, a DSL line, a cabletelevision line, a wireless communication channel, the Internet, etc.(which are viewed as being the same as or interchangeable with providingsuch software via a transportable storage medium). When implemented inhardware, the hardware may comprise one or more of discrete components,an integrated circuit, an application-specific integrated circuit(ASIC), etc.

While the present invention has been described with reference tospecific examples, which are intended to be illustrative only and not tobe limiting of the invention, it will be apparent to those of ordinaryskill in the art that changes, additions or deletions in addition tothose explicitly described above may be made to the disclosedembodiments without departing from the spirit and scope of theinvention.

What is claimed is:
 1. A method comprising: determining that a Bluetoothinquiry phase or a Bluetooth paging phase is beginning; in response todetermining that the Bluetooth inquiry phase or the Bluetooth pagingphase is beginning, sending, via a wireless local area network (WLAN)communication link, a power save indicator signal from a first device toa second device, wherein the power save indicator signal indicates thatthe first device is in a WLAN power save mode; and sending, via the WLANcommunication link, a first power save poll signal from the first deviceto the second device prior to a start of the Bluetooth inquiry phase orthe Bluetooth paging phase to prompt the second device to transmit afirst WLAN packet to the first device prior to the start.
 2. The methodof claim 1, wherein sending the first power save poll signal comprisescausing a power save enable signal to be active from a time of thedetermination that the Bluetooth inquiry phase or a Bluetooth pagingphase is beginning until a time DELTA before the start of the Bluetoothinquiry phase or the Bluetooth paging phase, where DELTA is a timeperiod based on an estimate of time required for i) transmission of thefirst power save poll signal, ii) receipt of an acknowledgment from thesecond device in response to the power save poll signal, and iii)receipt of the first WLAN packet, if one is available, from the seconddevice in response to the first power save poll signal.
 3. The method ofclaim 1, further comprising sending, via the WLAN communication link,one or more additional first power save poll signals from the firstdevice to the second device prior to the start of the Bluetooth inquiryphase or the Bluetooth paging phase to prompt the second device totransmit one or more additional first WLAN packets to the first deviceprior to the start.
 4. The method of claim 1, further comprisingsending, via the WLAN communication link, a second power save pollsignal from the first device to the second device during a gap betweenBluetooth inquiry phase message transmissions during the Bluetoothinquiry phase or between Bluetooth paging phase message transmissionsduring the Bluetooth paging phase to prompt the second device totransmit a second WLAN packet to the first device during the gap.
 5. Themethod of claim 4, wherein determining that the Bluetooth inquiry phaseor the Bluetooth paging phase is beginning comprises receiving anindication from a Bluetooth hardware device that the Bluetooth inquiryphase or the Bluetooth paging phase is beginning.
 6. The method of claim5, wherein: the indication from the Bluetooth hardware device indicatesthat the Bluetooth inquiry phase or the Bluetooth paging phase willbegin at a determined time T1 after the indication from the Bluetoothhardware device is received; and sending the first power save pollsignal comprises causing a power save enable signal to be active from atime of the determination that the Bluetooth inquiry phase or aBluetooth paging phase is beginning until a time T1−DELTA, where DELTAis a time period based on an estimate of time required for i)transmission of the first power save poll signal, ii) receipt of anacknowledgment from the second device in response to the power save pollsignal, and iii) receipt of the first WLAN packet, if one is available,from the second device in response to the first power save poll signal.7. The method of claim 4, further comprising determining timing of thegap based on the indication from the Bluetooth hardware device.
 8. Themethod of claim 7, further comprising receiving, from a Bluetoothhardware device, an indication indicating when the gap begins, whereindetermining timing of the gap is based on the indication.
 9. The methodof claim 4, further comprising sending, via the WLAN communication link,one or more additional second power save poll signals from the firstdevice to the second device during one or more corresponding additionalgaps between Bluetooth inquiry phase message transmissions during theBluetooth inquiry phase or between Bluetooth paging phase messagetransmissions during the Bluetooth paging phase to prompt the seconddevice to transmit one or more additional second WLAN packets to thefirst device during the additional gaps.
 10. The method of claim 1,further comprising: determining that the Bluetooth inquiry phase or theBluetooth paging phase ended; and in response to determining that theBluetooth inquiry phase or the Bluetooth paging phase ended, sending,via the WLAN communication link, a second signal from the first deviceto the second device, wherein the second signal indicates that the firstdevice is no longer in the WLAN power save mode.
 11. The method of claim1, wherein the power save indicator signal includes a packet having abit set to indicate that the first device is in the WLAN power savemode.
 12. The method of claim 11, wherein the packet is a null packet.13. An apparatus, comprising: a power save (PS) mode signal generator tocause a first PS mode signal to be sent from a first device to a seconddevice via a wireless local area network (WLAN) communication link inresponse to determining that a Bluetooth inquiry phase or a Bluetoothpaging phase is beginning, wherein the first PS mode signal indicatesthat the first device is in a WLAN PS mode; a timing device to generatean enable signal to be active from a time of the determination that theBluetooth inquiry phase or a Bluetooth paging phase is beginning until atime DELTA before a start of the Bluetooth inquiry phase or theBluetooth paging phase, where DELTA is a time period based on anestimate of time required for i) transmission of the first power savepoll signal, ii) receipt of an acknowledgment from the second device inresponse to the power save poll signal, and iii) receipt of the firstWLAN packet, if one is available, from the second device in response tothe first power save poll signal; and a PS poll signal generator coupledto the timing device, the PS poll signal generator configured to cause afirst PS poll signal to be sent from the first device to the seconddevice via the WLAN communication link prior to the start of theBluetooth inquiry phase or the Bluetooth paging phase to prompt thesecond device to transmit a first WLAN packet to the first device priorto the start based on the enable signal.
 14. The apparatus of claim 13,wherein the timing device is configured to generate the enable signalbased on a received indication that the Bluetooth inquiry phase or theBluetooth paging phase is beginning.
 15. The apparatus of claim 13,further comprising a Bluetooth control block configured to generate thereceived indication that the Bluetooth inquiry phase or the Bluetoothpaging phase is beginning.
 16. The apparatus of claim 13, wherein the PSpoll signal generator is configured to cause one or more additionalfirst power save poll signals to be sent from the first device to thesecond device prior to the start of the Bluetooth inquiry phase or theBluetooth paging phase to prompt the second device to transmit one ormore additional first WLAN packets to the first device prior to thestart.
 17. The apparatus of claim 13, wherein: the Bluetooth controlblock is configured to cause a gap between Bluetooth inquiry phasemessage transmissions during the Bluetooth inquiry phase or betweenBluetooth paging phase message transmissions during the Bluetooth pagingphase based on a puncturing pattern; the timing device is configured togenerate the enable signal during the gap; and the PS poll signalgenerator is configured to cause a second PS poll signal to be sent fromthe first device to the second device via the WLAN communication linkduring the gap to prompt the second device to transmit a second WLANpacket to the first device during the gap based on the enable signal.18. The apparatus of claim 17, wherein: the timing device is configuredto generate the enable signal during one or more additional gaps betweenBluetooth inquiry phase message transmissions during the Bluetoothinquiry phase or between Bluetooth paging phase message transmissionsduring the Bluetooth paging phase; and wherein the PS poll signalgenerator is configured to cause one or more corresponding additionalsecond PS poll signals to be sent from the first device to the seconddevice via the WLAN communication link in the one or more correspondingadditional gaps between Bluetooth inquiry phase message transmissionsduring the Bluetooth inquiry phase or between Bluetooth paging phasemessage transmissions during the Bluetooth paging phase to prompt thesecond device to transmit one or more additional second WLAN packets tothe first device during the additional gaps.
 19. The apparatus of claim13, wherein the PS mode signal generator is configured to cause a secondPS mode signal to be sent from the first device to the second device viathe WLAN communication link in response to an indication that theBluetooth inquiry phase or the Bluetooth paging phase ended, wherein thesecond PS mode signal indicates that the first device is not in the WLANPS mode.
 20. The apparatus of claim 13, wherein the PS mode signalgenerator is configured to cause the first PS mode signal to be sent ina null packet.
 21. A tangible, non-transitory computer readable mediumstoring instructions thereon that, when executed by a processor, causethe processor to: determine that a Bluetooth inquiry phase or aBluetooth paging phase is beginning; in response to determining that theBluetooth inquiry phase or the Bluetooth paging phase is beginning,cause a wireless local area network (WLAN) interface device of a firstcommunication device to transmit a power save indicator signal to asecond communication device, wherein the power save indicator signalindicates that the first communication device is in a WLAN power savemode; and cause the WLAN interface device to send a first power savepoll signal to the second communication device prior to a start of theBluetooth inquiry phase or the Bluetooth paging phase to prompt thesecond communication device to transmit a first WLAN packet to the firstcommunication device prior to the start.
 22. The tangible,non-transitory computer readable medium of claim 21, further storinginstructions thereon that, when executed by a processor, cause theprocessor to: cause a power save enable signal to be active from a timeof the determination that the Bluetooth inquiry phase or a Bluetoothpaging phase is beginning until a time DELTA before the start of theBluetooth inquiry phase or the Bluetooth paging phase, where DELTA is atime period based on an estimate of time required for i) transmission ofthe first power save poll signal, ii) receipt of an acknowledgment fromthe second device in response to the power save poll signal, and iii)receipt of the first WLAN packet, if one is available, from the seconddevice in response to the first power save poll signal.
 23. Thetangible, non-transitory computer readable medium of claim 21, furtherstoring instructions thereon that, when executed by a processor, causethe processor to: cause the WLAN interface device to send one or moreadditional first power save poll signals to the second communicationdevice prior to the start of the Bluetooth inquiry phase or theBluetooth paging phase to prompt the second communication device totransmit one or more additional first WLAN packets to the firstcommunication device prior to the start.
 24. The tangible,non-transitory computer readable medium of claim 21, further storinginstructions thereon that, when executed by a processor, cause theprocessor to: cause the WLAN interface device to send a second powersave poll signal to the second communication device during a gap betweenBluetooth inquiry phase message transmissions during the Bluetoothinquiry phase or between Bluetooth paging phase message transmissionsduring the Bluetooth paging phase to prompt the second communicationdevice to transmit a second WLAN packet to the first communicationdevice during the gap.
 25. The tangible, non-transitory computerreadable medium of claim 21, further storing instructions thereon that,when executed by a processor, cause the processor to: cause a power saveenable signal to be active from a time of a determination that theBluetooth inquiry phase or a Bluetooth paging phase is beginning until atime T1−DELTA, wherein an indication from a Bluetooth hardware deviceindicates i) that the Bluetooth inquiry phase or the Bluetooth pagingphase is beginning, and ii) that the Bluetooth inquiry phase or theBluetooth paging phase will begin at a determined time T1 after theindication from the Bluetooth hardware device is received, and DELTA isa time period based on an estimate of time required for i) transmissionof the first power save poll signal, ii) receipt of an acknowledgmentfrom the second communication device in response to the power save pollsignal, and iii) receipt of the first WLAN packet, if one is available,from the second communication device in response to the first power savepoll signal.
 26. The tangible, non-transitory computer readable mediumof claim 21, further storing instructions thereon that, when executed bya processor, cause the processor to determine timing of the gap based onan indication from a Bluetooth hardware device that the Bluetoothinquiry phase or the Bluetooth paging phase is beginning.
 27. Thetangible, non-transitory computer readable medium of claim 21, furtherstoring instructions thereon that, when executed by a processor, causethe processor to: cause the WLAN interface device to send one or moreadditional second power save poll signals to the second communicationdevice during one or more corresponding additional gaps betweenBluetooth inquiry phase message transmissions during the Bluetoothinquiry phase or between Bluetooth paging phase message transmissionsduring the Bluetooth paging phase to prompt the second communicationdevice to transmit one or more additional second WLAN packets to thefirst communication device during the additional gaps.
 28. The tangible,non-transitory computer readable medium of claim 21, further storinginstructions thereon that, when executed by a processor, cause theprocessor to: determine that the Bluetooth inquiry phase or theBluetooth paging phase ended; and in response to determining that theBluetooth inquiry phase or the Bluetooth paging phase ended, cause theWLAN interface device to send a second signal to the secondcommunication device, wherein the second signal indicates that the firstcommunication device is no longer in the WLAN power save mode.